Integrated circuit packaging technology continues to adjust to ever increasing complexity and density of integrated circuit devices mounted on a single circuit board or substrate. The new packaging designs are more compact in form factors, such as the physical size and shape of an integrated circuit, and providing a significant increase in overall integrated circuit density. However, integrated circuit density continues to be limited by the “real estate” available for mounting individual integrated circuits on a substrate. Even larger form factor systems, such as personal computers, compute servers, and storage servers, need more integrated circuits in the same or smaller “real estate”. Particularly acute, the needs for portable personal electronics, such as cell phones, digital cameras, music players, personal digital assistants, and location-based devices, have further driven the need for integrated circuit density.
This increased integrated circuit density has led to increased use of Ball Grid Array (BGA) packages and other such area array packages to provide the needed high density input/output external contact pads (I/Os). A typical area array package consist of an integrated circuit device mounted on a substrate, the substrate provides mechanical support for the individual integrated circuits and one or more layers of interconnect lines that enable the integrated circuits to be electrically connected to the I/O pads formed as an array of electrical contacts on the bottom surface of the substrate for connectivity to surrounding circuitry. A metal corner pad in one corner is typically used to identify the location of pin 1 of the array of I/O pads.
With the increasing use and expansion in array sizes of the BGAs, tests have shown that these area array packages are more commonly failing at the corner solder connections of these structures. The corner solder joints are susceptible to open joint failure due to environmental conditions, such as impact, bending, vibration, and thermal fatigue failure due to thermal-cycling conditions. A typical solution has been to increase the size of the corner solder ball joints. However, that may result in a corner structure larger than the rest of the solder balls in the array. Another solution is to increase the number of solder balls at the corner connections, but this leads to a risk of fusing these corner solder balls to adjacent solder balls impacting signal integrity.
Thus, a need still remains for an integrated circuit package system providing low cost manufacturing, improved yield, and thinner height for the integrated circuits. In view of the ever-increasing need to save costs and improve efficiencies, it is more and more critical that answers be found to these problems.
Solutions to these problems have been long sought but prior developments have not taught or suggested any solutions and, thus, solutions to these problems have long eluded those skilled in the art.